This invention relates to an apparatus for the measuring of human respiration. More particularly, it relates to a device for measuring the volume of air entering human lungs.
There are known in the art devices for human respiratory exercise or for the practice of breath control. Devices of these types are disclosed, for example, in Tunbull, U.S. Pat. No. 3,811,671, Russo, U.S. Pat. No. 4,086,918, Hanson, U.S. Pat. No. 3,695,608 and Russo, U.S. Pat. No. 4,060,074. Such devices typically involve the exhalation of air into, or inhalation of air from an enclosed chamber.
Also known are instruments for the purpose of measuring the amount of air entering or leaving human lungs. Such instruments are sometimes referred to as spirometers. Particular examples are disclosed in McMillan, U.S. Pat. No. 3,722,506, Rand, et al., U.S. Pat. No. 3,635,214 and Ruskin, et al., U.S. Pat. No. 3,826,247.
Many spirometer devices are costly and cumbersome. Although newer, more portable instruments are now available, there remains a need for volumetric spirometers which are accurate and reliable, yet relatively inexpensive and easily transportable.